Error trying to read a region from a very large image file in java

Question

I need to read a very large image file (56000 px X 49000 px). I need to read it in small rectangular chunks, so I am trying to follow this example: Read region from very large image file in Java

However, I get this error: java.lang.IllegalArgumentException: width*height > Integer.MAX_VALUE!

My code snippet is below (taken more or less exactly from the link above):

ImageInputStream stream = null;
    try {
        stream = ImageIO.createImageInputStream(new File(this.inFile)); // File or input stream
    } catch (Exception ex) {
        Logger.getLogger(CreateTrainingSetFromImage.class.getName()).log(Level.SEVERE, null, ex);
    }
    Iterator<ImageReader> readers = ImageIO.getImageReaders(stream);

    ImageReader r = readers.next();
    System.out.println("Using reader: " + r);
    r.setInput(stream);
    try {
        System.out.println("Height = " + r.getHeight(0));
        System.out.println("Width = " + r.getWidth(0));
    } catch (IOException ex) {
        Logger.getLogger(CreateTrainingSetFromImage.class.getName()).log(Level.SEVERE, null, ex);
    }

ImageReadParam param = r.getDefaultReadParam();
Rectangle sourceRegion = new Rectangle(0, 0, 200, 200);
param.setSourceRegion(sourceRegion); // Set region

        BufferedImage image = null;
        try {
            image = r.read(0, param); // Will read only the region specified
            System.out.println("Read file " + this.inFile);
            System.out.println("Width = " + image.getWidth());
            System.out.println("Height = " + image.getHeight());
        } catch (Exception ex) {
            Logger.getLogger(CreateTrainingSetFromImage.class.getName()).log(Level.SEVERE, null, ex);
        }

My understanding is that specifying the Rectangle sourceRegion for param would make the ImageReader read only that small chunk of the image, so I don't understand what's causing the error. Any help would be much appreciated. If it helps, I am using the TwelveMonkeys ImageIO plugins.

Here is the output:

Using reader: com.twelvemonkeys.imageio.plugins.jpeg.JPEGImageReader@5437dd04
Height = 49429
Width = 56281
Apr 23, 2017 11:57:17 AM createtrainingsetfromimage.CreateTrainingSetFromImage    test
SEVERE: null
java.lang.IllegalArgumentException: width*height > Integer.MAX_VALUE!
at javax.imageio.ImageReader.getDestination(ImageReader.java:2840)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readInternal(JPEGImageReader.java:1066)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.read(JPEGImageReader.java:1034)
at com.twelvemonkeys.imageio.plugins.jpeg.JPEGImageReader.read(JPEGImageReader.java:382)
at createtrainingsetfromimage.CreateTrainingSetFromImage.test(CreateTrainingSetFromImage.java:102)
at createtrainingsetfromimage.CreateTrainingSetFromImage.createTrainingSet(CreateTrainingSetFromImage.java:168)
at createtrainingsetfromimage.CreateTrainingSetFromImage.main(CreateTrainingSetFromImage.java:46)

Answer 1

There's a known bug/limitation in the getDestination method of the ImageReader base class (the super class of the JPEGImageReader and all other ImageIO reader implementations), that calculates the width * height of the input image, rather than the region you are actually trying to read... This prevents you from reading even small parts of such images.

The code looks like this, and the width and height parameters are the dimensions of the input:

if ((long) width * height > Integer.MAX_VALUE) {
    throw new IllegalArgumentException("width*height > Integer.MAX_VALUE!");
}

In most of my (the TwelveMonkeys ImageIO library's) ImageReaders I work around this limitation by using a different implementation of the getDestination method. But for the JPEGImageReader I delegate the actual decoding to the com.sun....JPEGImageReader, which uses the original method, and causes this exception.

It might be possible to work around the problem by using the readRaster method instead of read (as it does not use the getDestination method), but it requires extra work, and I haven't had the possibility to test this yet.